1. Field
One or more example embodiments of the following description relate to a method and apparatus for encoding or decoding an audio signal such as a speech signal or a music signal, and more particularly, to a method and apparatus for encoding or decoding a signal corresponding to a high-frequency domain among audio signals.
2. Description of the Related Art
A signal corresponding to a high-frequency domain is less sensitive to a fine structure of a frequency than a signal corresponding to a low-frequency domain. Accordingly, there is a need to increase an encoding efficiency to overcome a restriction of bits available when encoding an audio signal. Thus, a large number of bits may be allocated to a signal corresponding to a low-frequency domain, while a smaller number of bits may be allocated to a signal corresponding to a high-frequency domain.
Such a scheme may be applied to a Spectral Band Replication (SBR) technology. SBR technology may be used to improve encoding efficiency by representing high-band component signals as an envelope, and by synthesizing the high-band component signals during the decoding of the high-band component signals, based on a fact that an auditory sense of a human being has a relatively low resolution in a high-band signal.
In SBR technology, there is a demand for an improved method for extending a bandwidth of a high-frequency domain.